How picky are these things about the frequency? I should be able to get a PIC to output close to 38KHz but it wont be exact and the chip will be doing PWM on other outputs aswell as sending and receiving serial data so it might change a lot.

When you say "cycle" i assume you mean the emitter turning off and back on again (not an instruction cycle on the PIC).

Ive got some transistors i can use to drive the emitters so that bits ok.

Would i be able to do this without the lenses? I might be able to find some of those IR filters somewhere but i cant think of anywhere i could get magnifying lenses from

Ill add a few of the ones i mentioned before to my next order so i can do some more tests